N522: Duplicate of a crossover claim

What causes N522?

• The claim was billed to the secondary directly while Medicare’s crossover was still in flight
• The patient’s supplemental plan is on file with Medicare for automatic crossover, and the office bills secondaries by hand
• A corrected claim sent to the secondary without waiting for the crossover copy to adjudicate

How do you fix a N522 remark code?

1. Do nothing to this claim. Find the crossover copy — the Medicare remittance carries MA18 when it forwarded the claim — and post from the secondary’s remittance when that copy adjudicates.
2. If the crossover copy never appears after a reasonable wait, bill the secondary with the Medicare remittance attached and say in the claim notes that no crossover was received.
3. Stop manual secondary billing for patients whose supplemental plan crosses over automatically; the Medicare remittance tells you which ones.

Can N522 be prevented?

Flag crossover patients in the practice management system and route their secondaries to a hold queue that waits for the crossover remittance.

A denial like this one is the recurring cost that medical billing outsourcing is built to take off your desk — a dedicated seat working the queue instead of it waiting for whoever has a free hour.

Codes worked the same way

N522 is fixed at coordination of benefits and rebilled. So are these, which is why a queue sorted by recovery route moves faster than one sorted by code number — the same person, in the same system, with the same evidence to hand, clears all of them in one pass.

• CO-22 — May be covered by another payer
• CO-27 — Coverage had already ended
• CO-109 — Wrong payer or contractor
• CO-119 — Benefit maximum reached
• PR-31 — Patient not found as insured
• CO-24 — Covered under capitation

Specialties that name this among their costliest

These are specialties whose own worst denials include one of this kind. The line under each is the denial they name, quoted from their page so you can see what the link is based on.

• Behavioral Health
  Add-on codes billed without the primary service
• Podiatry
  Orthotics denied for coverage exclusion
• Obstetrics & Gynecology
  Coverage checked once at the first prenatal visit and never rechecked, so the delivery claim months later goes to a plan the patient has already left.
• Urgent Care
  Coverage taken from whatever card the walk-in hands over at the desk and never checked against the plan, so the claim goes to a policy the patient left months ago
• Primary Care
  Low-dollar denials — the patient assigned to a different primary care provider, a wrong place of service — left in the queue as not worth the call, then aged past timely filing.
• Clinical Laboratory and Pathology
  Tests denied for a diagnosis not on the coverage policy's approved list

What leaving it costs

Working a denied claim costs $57.23 per denied claim in administrative time (source) — before any of it is recovered, and whether or not it ever is.

Payers ultimately pay roughly 90% of claims even while using an initial denial to slow payment (source), so the reason one sits is rarely that nobody knows how to work it. Put your own denial count in.

Questions

Code descriptions are the standard X12 claim adjustment reason and remittance advice remark code text. Payer policies differ, and the payer’s own coverage policy governs any individual claim. This page is working guidance, not legal or clinical advice.